RESUMEN
BACKGROUND: Serious complications, such as emboli and mycotic aneurysms, are still frequent in documented cases of infective endocarditis. Infecting organisms other than Streptococcus viridans and Staphylococcus are becoming more common. CASE REPORT: A 8 year-old girl was admitted because of a sudden pain in the right calf followed by complete disability. She had low-grade fever and presented with a moderate heart murmur with no sign of congestive heart failure, a severe pain at palpation of her calf with no Homans sign; she had many dental caries. Laboratory data indicated leukocytosis with increased percentage of polymorphonuclear cells and increased sedimentation rate. Ultrasonography of the calf showed laceration of the muscle with blood suffusion. Echocardiography showed vegetations involving the mitral valve. Intravenous antibiotic therapy with penicillin G and netilmicin was instituted, but mitral insufficiency appeared 7 days later while the fever persisted. At that time, the brain CT scan showed ischemic lesions, while angiography showed several mycotic aneurysms. Neisseria mucosa was recovered from the 5 initial blood cultures 16 days after the onset, and penicillin G was replaced by ampicillin. A second vegetation involving the aortic valve was seen a few days later, and a recent arterial embolism to the right leg was suspected because fever and pain reappeared. The brain ischemic lesions gradually disappeared and a second angiography performed 3 months after the first showed that all but one large mycotic aneurysm had disappeared; this last aneurysm was excised. Four years later, the child is in good health without any neurological sequelae but having mitral insufficiency. CONCLUSION: This girl presented with classical complication of infective endocarditis due to Neisseria mucosa, a saprophytic organism of the oral cavity. This is the second report of such an infection in children.